1. Field of the Invention
The invention relates to an electric machine for a hybrid or electric vehicle. The electric machine has an external rotor and a stator arranged within a rotor. The rotor has a rotor carrier, rotor plates and permanent magnets. The rotor carrier has a first, radially extending carrier section and a second, axially extending carrier section connected thereto. The second carrier section bears the rotor plates and the permanent magnets. The stator has stator plates and wire windings. The wire windings form winding heads that extend axially on both sides over the stator plates. An impeller wheel is connected to the rotor carrier.
2. Description of the Related Art
DE 195 13 134 A1 discloses the above-described electric machine. The impeller wheel of the electric machine of DE 195 13 134 A1 is molded integrally and protrudes freely toward the outside into a floor of the rotor carrier which is configured in a beaker shape. Cooling air is sucked into the beaker-shaped rotor carrier and forced through the stator when the impeller wheel rotates, thereby ensuring sufficient cooling of the winding heads of the stator. The impeller wheel is arranged between the winding heads, which are arranged on an axial side of the stator, and a bell-shaped cover housing, which is fit over the rotor. The cover housing has an air inlet duct on the floor of the rotor carrier in the region of the impeller wheel and air outlet openings for the cooling air at an attachment end having an end plate.
The impeller wheel of this known electric machine is arranged axially next to the winding heads. Thus, the electric machine disadvantageously has a relatively large axial extent. In this context, additional axial installation space is required for the impeller wheel and therefore is not utilized for other components of the electric machine that are functionally absolutely necessary. Given a specific power level of the electric machine, a relatively large axial extent of the electric machine is therefore required.
The object of the invention is to provide an electric machine that has a high power level accompanied by a short axial extent and that has optimum air cooling in the region of the rotor and stator.